Variable speed transmission and method of use

ABSTRACT

A variable speed transmission includes an actuator mechanism that can be remotely activated to cause engagement of a drive unit and to subsequently vary the speed of the drive unit using the same activation mechanism. The variable speed transmission can include a first pulley that has a first and second face that are movable relative to each other by activation of the actuator mechanism. When the first and second faces of the first pulley are located in a first position, a belt located on the first pulley remains motionless. The first and second faces can be moved by the actuator mechanism into a second position where the first and second plates engage the belt with enough frictional force to cause the belt to start moving about the first pulley. The first and second faces of the first pulley can also be moved between the second position and a third position such that the space between the faces becomes smaller. As the space between the faces becomes smaller, the belt moves outward and away from the rotational axis of the pulley, thus moving about the axis faster as the space between the faces gets smaller.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to power equipment, including butnot limited to mowers, tillers, snow blowers, and tractors, and moreparticularly, to a variable speed transmission and method for using thevariable speed transmission.

[0003] 2. Discussion of Related Art

[0004] Conventional power equipment such as lawn mowers, snow blowers,mulchers, etc. often include “self-propulsion” mechanisms forautomatically driving the wheel, track or other drive mechanism used topropel the power equipment. Typically, the self-propulsion drivemechanism is activated by engaging a transmission thatconnects/disconnects the transmission shaft to the drive wheel. Thespeed of the drive wheel varies proportionally with the speed of theengine. Accordingly, the speed of the drive wheel can only be varied bychanging the throttle position or by changing the gear ratios inside thetransmission to increase/decrease the speed of the engine.

[0005] Recently it has become desirable to provide all types of powerequipment with variable speed transmissions in order to smoothly varythe drive speed of the power equipment without increasing/decreasingengine speed to vary the drive speed. One attempt at providing such adevice is currently incorporated in power equipment produced and sold inEurope by France Reductor, Inc. Idler pulley systems have also been usedin an attempt to provide variable speed power equipment.

[0006] The France Reductor VST includes a first belt that is attachedbetween a drive pulley on the engine output shaft and a driven pulley ona rotational shaft. A second pulley is attached to the same rotationalshaft as the driven pulley and is locked and rotates synchronously withthe driven pulley. A second belt is attached between the second pulleyand a second driven pulley connected to a transmission shaft. Thetransmission shaft is connected to a transmission that transmitsrotational power to a drive wheel or other drive mechanism. A clutchlocated in this transmission can be actuated to engage/disengage thetransmission and transmit/disengage rotational power to the drivemechanism.

[0007] In order to vary the speed of the drive mechanism, a platesupporting the rotational shaft can be moved against the bias of aspring to tension and loosen the first belt and second belt,respectively. The first driven pulley and the second drive pulley (bothof which are located on the same rotational shaft) have variable widthgrooves that are caused to vary when their respective belts aretensioned and loosened. Accordingly, when the first belt is tensioned,the first belt moves deeper into the groove of the first pulley towardsthe rotational axis of the rotational shaft, thus rotating therotational shaft at ever increasing speeds as tension in the beltincreases. Likewise, when the second belt is simultaneously loosened,the groove in the second drive pulley becomes narrower and the secondbelt moves out of the groove and away from the rotational axis of therotational shaft, thus increasing the speed of the second belt andultimately increasing the speed of the drive mechanism. Two belts arerequired in such a system to provide the necessary increase in variablespeed output for the power equipment drive mechanism. In addition, twocontrol mechanisms are necessary such that one control mechanism canactuate the transmission and one control mechanism can vary the speed ofthe transmission.

[0008] Because the France Reductor VST system requires two belts, fourpulleys, two control mechanisms and a separate clutched transmission,the cost of the system and the space requirements are both relativelyhigh. It is usually necessary to mount this VST system on top of ahousing structure in order to fit such a large system on powerequipment. In addition, the many different parts make the systemsusceptible to mechanical failures and creates problems with the rangeof aesthetic design available to power equipment that incorporates sucha system. Furthermore, the actuation of the system is a two stepprocess, and speed variation can be sudden at times if the transmissionand the variable speed actuation mechanisms are not actuated in thecorrect order. The belts are also constantly moving in this related artVST system.

[0009] Another type of VST system that is commonly used in powerequipment includes a hydrostatic transmission for varying the speedoutput to a drive unit. In such a system, a single control mechanism canbe used to vary the speed of a drive unit from a neutral position tomaximum speed. However, such transmissions are relatively expensive tomanufacture. In addition, maintenance and repair of such a system aresignificantly more difficult and expensive than maintenance and repairof belt drive and/or geared transmission systems.

SUMMARY OF THE INVENTION

[0010] Accordingly, the present invention is directed to a variablespeed transmission that substantially obviates one or more of theproblems due to limitations and disadvantages of the related art.

[0011] An object of the present invention is to provide an efficient,inexpensive and compact variable speed transmission that can be actuatedfrom a neutral position through a full speed position by a singleactuator mechanism.

[0012] Another object of the invention is to incorporate the belt intothe clutch mechanism of the variable speed transmission.

[0013] A further object of the invention is to provide a compact singleactuation variable speed transmission that is capable of producing arelatively high level of output speed;

[0014] Another object of the present invention is to provide a compactassembly that can be easily and adequately shielded and requires as fewparts as possible.

[0015] A still further object of the present invention is to minimizethe number of pulleys and belts necessary, and to provide a variablespeed transmission that uses a single belt connected between two pulleyssuch that the amount of moving parts is reduced and the possibility ofmalfunctions are reduced.

[0016] An additional object of the invention is to provide a controlmechanism that varies drive speed between a neutral, intermediate andfull speed position while also being variably operable between thesethree separate positions.

[0017] Another object of the invention is to vary the speed of a drivemechanism for power equipment in a smooth and reliable manner.

[0018] A still further object of the invention is to provide a compactsingle actuator mechanism that controls the output speed to a drivemechanism from zero to a maximum speed by moving the actuator mechanismin a single uniform motion.

[0019] Another object of the invention is to incorporate the variablespeed transmission into the drive shaft of a motor such that a compactarrangement of the transmission.can be achieved.

[0020] Additional features and advantages of the invention will be setforth in the description which follows, and in part will be apparentfrom the description and claims hereof as well as the appended drawings.

[0021] To achieve these and other advantages and in accordance with thepurpose of the present invention, as embodied and broadly described, avariable speed transmission includes: a first pulley having a rotationalaxis and including a first face and a second face, the first face beingmovable with respect to the second face; a belt located adjacent thefirst face and the second face of the first pulley; and an actuatorlocated adjacent the first pulley and adapted to move the first face tomove with respect to the second face between a neutral position, anintermediate position and a full speed position, the neutral positiondefined by the first face being located at a first position with respectto the second face, and the first face being rotatable relative to thesecond face, the intermediate position defined by the first face beinglocated at a second position that is closer to the second face than whenthe first face is located at the first position, the belt being infrictional engagement with the first face and second face such thatmotion of one of the first face, second face and belt causes another oneof the first face, second face and belt to move, and the full speedposition defined by the first face being located at a third positionthat is closer to the second face than when the first face is located atthe second position, the belt being located in a position further fromthe rotational axis of the first pulley than when the first face islocated at the second position.

[0022] The invention also includes a variable speed transmission forcontinuously varying the output speed of a drive wheel from zero to anupper speed limit, which includes: a single control mechanism capable ofcontrolling the speed of the drive wheel from zero to the upper speedlimit; an actuator connected to the control mechanism; and a drive trainoperationally connected between the control mechanism and the drivewheel, wherein the drive train includes a first and second pulley and nomore than one belt.

[0023] In addition, the invention includes a variable speed transmissionfor continuously varying the output speed of a drive wheel from zero toan upper speed limit, which includes: a single control mechanism capableof controlling the speed of the drive wheel from the upper speed limitto zero; an actuator connected to the control mechanism; and a drivetrain operationally connected between the control mechanism and thedrive wheel, wherein the drive train includes a first and second pulleyconnected by a belt, the first pulley having a rotational axis, a firstface and a second face, the first face being movable with respect to thesecond face; wherein the actuator is located adjacent the first pulleyand capable of causing the first face to move with respect to the secondface between a neutral position, an intermediate position and a fullspeed position, the neutral position defined by the first face beinglocated at a first position with respect to the second face, androtatable with respect to the first face, the intermediate positiondefined by the first face being located at a second position that iscloser to the second face than when the first face is located at thefirst position, the belt being in frictional engagement with the firstface and second face such that motion of one of the first face, secondface and belt causes another one of the first face, second face and beltto move, and the full speed position defined by the first face beinglocated at a third position that is closer to the second face than whenthe first face is located at the second position, the belt being locatedin a position further from the rotational axis of the first pulley thanwhen the first face and second face are in the intermediate position.

[0024] Furthermore, the invention can include a variable speedtransmission, that includes: a first pulley having a rotational axis andincluding a first face and a second face, the first face being movablewith respect to the second face; a second pulley having a second pulleyrotational axis and including a primary face and a secondary face; abelt located on the first pulley and second pulley; and an actuatorlocated adjacent the first pulley and adapted to move the first facewith respect to the second face between a neutral position and a driveposition, the neutral position is defined by the first face beinglocated at a first position with respect to the second face, and thefirst face being rotatable with respect to the second face, the driveposition is defined by the first face and second face being frictionallyengaged with the belt such that the first face, second face and beltrotate together.

[0025] The invention can also include a variable speed transmission,including: a first pulley having a rotational axis and including a firstface and a second face, the first face being movable with respect to thesecond face; a second pulley having a second pulley rotational axis andincluding a primary face and a secondary face, the primary face beingmovable with respect to the secondary face along the second pulleyrotational axis; a biasing mechanism located adjacent one of the primaryface and secondary face of the second pulley and adapted to bias theprimary face towards the secondary face; a belt located on the firstpulley and second pulley; and an actuator located adjacent the firstpulley and adapted to move the first face with respect to the secondface between a neutral position and a drive position, the neutralposition is defined by the first face being located at a first positionwith respect to the second face, and the first face being rotatable withrespect to the second face, the drive position is defined by the firstface and second face being frictionally engaged with the belt such thatthe first face, second face and belt rotate together.

[0026] Additionally, the invention can include a method for using avariable speed transmission that includes a first pulley having arotational axis, a first face and a second face, the first face beingmovable along the rotational axis with respect to the second face, abelt located adjacent the first face and the second face of the firstpulley, the method including driving one of the first face, the secondface and the belt about the rotational axis of the first pulley; movingthe first face along the rotational axis and relative to the second facesuch that a portion of each of the first face and the second facefrictionally engages the belt to cause one of the first face, the secondface and the belt to begin movement about the rotational axis of thefirst pulley; and moving the belt away from the rotational axis of thefirst pulley to cause the belt to move faster about the rotational axisof the first pulley.

[0027] The invention can also include a method for using a variablespeed transmission that includes a first pulley having a rotationalaxis, a first face and a second face, the first face being movable alongthe rotational axis with respect to the second face, a second pulleyhaving a second pulley rotational axis, a primary face and a secondaryface, the primary face being movable with respect to the secondary facealong the second pulley rotational axis, a belt connected between thefirst pulley and the second pulley, including: driving one of the firstface, the second face and the belt about the rotational axis of thefirst pulley; moving the first face along the rotational axis andrelative to the second face such that a portion of each of the firstface and the second face frictionally releases from the belt to causeone of the first face, the second face and the belt to begin movementrelative to another one of the first face, the second face and the belt.

[0028] The invention can also include a method for using a variablespeed transmission to drive a propulsion mechanism on a piece of powerequipment, including: providing a control mechanism that is connected toa drive train which drives the propulsion mechanism, the drive trainincluding a first pulley having a rotational axis, a first sheave and asecond sheave, and a belt having an inner surface located around thefirst pulley; permitting the first sheave to remain substantiallystationary relative to the second sheave; rotating the first sheave ofthe first pulley with respect to the belt; and engaging the belt withthe first sheave of the first pulley with enough force to begin movementof the belt about the first pulley.

[0029] It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary andexplanatory and are intended to provide further explanation of theinvention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are included to provide afurther understanding of the invention and are incorporated in andconstitute a part of this specification, illustrate embodiments of theinvention and together with the description serve to explain theprinciples of the invention. In the drawings:

[0031]FIG. 1 is an isometric view of a variable speed transmission madein accordance with the principles of the invention;

[0032]FIG. 2 is an isometric view of the actuator and first pulleyarrangement of FIG. 1;

[0033]FIG. 3 is a top view of the actuator and first pulley arrangementof FIG. 1;

[0034]FIG. 4 is a side view of the actuator and first pulley arrangementof FIG. 1;

[0035]FIG. 5 is an operational side view of the actuator and firstpulley arrangement of FIG. 1 in a neutral position;

[0036]FIG. 6 is an operational side view of the actuator and firstpulley arrangement of FIG. 1 in a full speed position;

[0037]FIG. 7 is an operational second side view of the actuator andfirst pulley arrangement of FIG. 1 in an intermediate position;

[0038]FIG. 8 is an isometric view of the second pulley of FIG. 1;

[0039]FIG. 9 is a side view of the second pulley of FIG. 1;

[0040]FIG. 10 is a disassembled view of the second pulley of FIG. 1;

[0041]FIG. 11 is a cross-sectional split view of another embodiment ofthe actuator and first pulley assembly;

[0042]FIG. 12 is a cross-sectional split view of another embodiment ofthe actuator and first pulley assembly;

[0043]FIG. 13 is a cross-sectional split view of another embodiment ofthe actuator and first pulley assembly; and

[0044]FIG. 14 is a cross-sectional split view of another embodiment ofthe actuator and first pulley assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] Reference will now be made in detail to the preferred embodimentsof the present invention, an example of which is illustrated in theaccompanying drawings.

[0046]FIG. 1 illustrates an isometric top view of a preferred embodimentof the variable speed transmission (VST). The VST includes a firstpulley 100 and actuator 400 connected to an engine output drive shaft600. A belt 300 connects the first pulley 100 to a second pulley 200,which in turn is connected to a drive mechanism for the associated pieceof power equipment. Thus, the rotational energy from the engine outputdrive shaft 600 can be transmitted to the drive mechanism via a firstpulley 100, actuator 400, belt 300 and a second pulley 200. A controlmechanism 500 can be attached to the actuator 400 to vary the outputspeed of the drive mechanism from about zero to anengagement/intermediate position speed and then proceed to a maximum orfull speed. The control mechanism 500 varies the range of output speedof the drive mechanism by causing the actuator 400 to change respectivethe groove width of the first and second pulleys 100, 200, thus changingthe radius of rotation of the belt 300 about the first and secondpulleys 100 and 200, as explained in greater detail below. In addition,the present invention provides a neutral position in which therotational energy of the drive shaft 600 is disengaged from the drivemechanism of the power equipment. This neutral position is realized byusing the belt 300 as a “clutch,” which will also be explained ingreater detail below.

[0047] An actuator (not shown) connected to the control mechanism 500permits an operator of the power equipment to control actuation of theactuator 400, and to ultimately control the actuation and variance ofthe speed output by the drive mechanism of the power equipment. Theactuator is preferably controlled using a single motion to move theactuator between a neutral position and a full speed position. One typeof actuator that can be used is a U-shaped bar type actuator pivoted toa U-shaped handle of the power equipment. This type of actuator iscontrolled by squeezing the U-shaped bar and pivoting it with respect tothe U-shaped handle to cause a control line 515 to move relative to thehandle. When the U-shaped actuator bar becomes flush with and/orcoplanar with the U-shaped handle, the control mechanism 500 causes theactuator 400 to be at its maximum speed position. When the U-shapedactuator bar is pivoted to its furthest angled position with respect tothe U-shaped handle, the actuator is in its neutral position. Thus, theoperator can propel the power equipment from zero to maximum speed bysqueezing and/or otherwise moving the U-shaped actuator bar to pivot itwith respect to the U-shaped handle. Of course, other actuators such asa rotary knob or pivoting lever could be used in place of the U-shapedbar actuator to control the speed of the power equipment between zeroand maximum speed.

[0048] As shown in FIGS. 2-7, the actuator 400 can include a firstactuator plate 410 and a second actuator plate 420, each of which canrotate with respect to the other upon activation of the controlmechanism 500. The first actuator plate 410 can include an extensionlock member 417 on its top surface 413 for locking the first actuatorplate to the housing or other element of the power equipment. Thus, thesecond actuator plate 420 will be able to rotate with respect to boththe first actuator plate 410 and the power equipment device in general.Alternatively, the first actuator plate 410 could be rotatable withrespect to both the second actuator plate 420 and the power equipmentdevice in general. Bearings 404 permit both the first and secondactuator plate to rotate relative to the drive shaft 600 located inshaftway 403 of the actuator plates 410 and 420. The bearings 404 can bethe same or different style bearings and can be selected to conform tothe necessary performance characteristics desired for a particularapplication of the invention. In addition, when economicalconsiderations mandate, it is possible in some circumstances to not usebearings or consolidate various bearings. A retaining clip 601 can beprovided to keep the actuator 400 in position on the drive shaft 600.

[0049] The control mechanism 500 is preferably connected to the actuator400 by an attachment ball 517 that is locked into a mating actuatorcutout 426 in the second actuator plate 420. A cable retainer 510 can befixed to an actuator extension 418 on the first actuator plate 410 byinserting a lock nub 512 that extends from the cable retainer 510 intoan aperture in the extension 418 of the first actuator plate 410. Acontrol cable (or control line) 515 located within the cable retainer510 can move relative to the cable retainer 510 and the first actuatorplate 410. Accordingly, movement of the control line 515 causes thesecond actuator plate 420 to move/rotate with respect to the firstactuator plate 410. A ball/ramp mechanism 443 (see FIG. 3) can be usedin combination with an actuator spring 430 to bias the second actuatorplate 420 to its initial position with respect to the first actuatorplate 410 when tension in the control line 515 is released.

[0050] The ball/ramp mechanism 443 includes balls 440 located betweenthe actuator plates 410 and 420 which ride up respective ramps 441located in one of the first and second actuator plates 410 and 420. Asthe second plate 420 rotates with respect to the first actuator plate410, the balls 403 ride up the ramps 441 and cause the second actuatorplate 420 to separate and move away from the first actuator plate 410against the bias of springs 430. Springs 430 are attached to the firstactuator plate 410 and extend through slots 427 located in a springwayportion 423 of the second actuator plate 420. The slots 427 are shapedto allow the springs 430 to ride along the lower surface 424 of thesecond actuator plate 420 as the second actuator plate 420 rotatesrelative to the first actuator plate 410. The springs 430 bias thesecond actuator plate 420 towards the first actuator plate 410throughout rotation of the plates. The springs 430 are connected to thefirst actuator plate 410 by inserting a portion of each spring 430 intoa spring lockhole 416 in the top surface of the first actuator plate410. The spring 430 extends downward through a spring slot 415 in thefirst actuator plate 410.

[0051] The rotation of the first actuator plate 410 with respect to thesecond actuator plate 420 can be limited by providing abutments 412 and422 in the respective first and second actuator plates 410 and 420,respectively. The abutments 412 and 422 ride in slideways 421 and 411,respectively, of the opposing first and second actuator plates 420 and410. Thus, the rotation of the first and second actuator plates 420 and410 is limited by the length of the slideways 411 and 421 and the lengthof their corresponding abutments 422 and 412.

[0052] The first pulley 100 includes a first sheave 110 and a secondsheave 120 which form a groove 130 therebetween. The second sheave 120can be connected to rotate with the drive shaft 600 such that both thesecond sheave 120 and drive shaft 600 rotate with respect to the firstsheave 110 of the first pulley 100. The first sheave 110 can also rotatewith respect to the drive shaft 600 and with respect to the secondactuator plate 420. Bearings 404 can be provided between both the firstsheave 110 and drive shaft 600 and between the first sheave 110 andsecond actuator plate 420 to facilitate their relative rotation. As thesecond actuator plate 420 moves downward by action of the controlmechanism 500, it forces the first sheave 110 of the first pulleytowards the second sheave 120 of the first pulley, which decreases thewidth of the groove 130 of the first pulley 100. As the groove widthnarrows, the belt 300 is engaged with a face 121 of the second sheave120 of the first pulley 100. The belt 300 becomes tensioned as itengages the face 121 and begins to rotate about the rotational axis ofthe first pulley 100 due to frictional force between the rotating face121 and belt surface. This action is what is referred to above as usingthe belt 300 as a clutch mechanism.

[0053] The groove 130 can be further narrowed by moving the controlmechanism 500 to force further separation of the actuator plates 410 and420, which forces the first sheave 110 closer to the second sheave 120of the first pulley. The faces 111 and 121 of the first and secondsheave 110 and 120 include angled surfaces 114 and 214. As the first andsecond sheave 110 and 120 move towards each other, the belt is forced torise radially along these angled surfaces 114 and 124 out of the groove130. Thus, as the pulley first sheave 110 and pulley second sheave 120move towards each other, the belt 300 moves away from the rotationalaxis of the drive shaft 600 and the rotational speed of the beltincreases. The drive mechanism is at maximum speed when the belt 300 isat a furthest position from the rotation axis and the first sheave 110is closest to the second sheave 120 of the first pulley.

[0054] The first pulley sheave 110 can also include an extension surface112 that extends along the rotational axis of the drive shaft 600 andbetween the first angled surface 114 and second angled surface 124 ofthe first and second sheaves 110, 120. When the invention is in itsneutral position (e.g., when no actuation force is applied to thecontrol mechanism 500, the first and second actuator plates 410 and 420are together, and the first and second sheave of the first pulley 110and 120 are at their widest position), the belt 300 tension causes thegroove in the first pulley to return to its widest position, and thebelt 300 rests on the extension surface 112. The drive mechanism remainseffectively at a geared idle or geared neutral state.

[0055] The belt 300 is preferably connected between and supplies powerfrom the drive shaft 600 to the second pulley 200. The second pulley 200can be connected to a drive mechanism of the power equipment forpropelling the equipment.

[0056] As shown in FIGS. 8-10, the second pulley 200 can include asecond pulley first sheave 210 that can be connected to and rotate witha second pulley second sheave 220. A hub 227 can be formed in the secondpulley second sheave 220 and shaped to extend through a keyway 218 in acollar 217 of the second pulley first sheave 210. The relative shape ofthe hub 227 and keyway 218 rotationally lock the sheaves 210 and 220together. The hub 227 includes a shaftway 225 for connection to a drivenshaft of the drive mechanism. When the second pulley first sheave 210 isconnected to the second pulley second sheave 220, an attachment disk 250can be attached to the hub 227 of the second pulley second sheave 220 tokeep the first and second sheaves 210 and 220 together. The attachmentdisk 250 can be attached to the hub 227 by a number of screws 253 thatextend though holes 251 in the disk 250 and attach to screw holes 223 inthe hub 227 of the second sheave 220. Various shaped hubs can be used inthe invention, including a single key 20 hub.

[0057] A spring 240, which can be a diaphragm type or belleville spring,can be located between the attachment disk 250 and a top surface 216 ofthe first sheave 210 to bias the first sheave 210 towards the secondsheave 220 of the second pulley. The spring 240 rides along the outsideof collar 217 in the second pulley first sheave 210 and can include anupper ring 241 and lower ring 242 separated from each other by anintermediate leaflet 243. The upper and lower rings 241 and 242 lie flaton the lower surface of the attachment disk 250 and the top surface 216of the first sheave 210, respectively. The spring 240 permits the groove230 formed between the first sheave 210 and second sheave 220 of thesecond pulley 200 to vary in width in accordance with the tension in thebelt 300.

[0058] The belt 300 can ride between a first face 211 of the firstsheave 210 and a second face 221 of the second sheave 220 of the secondpulley 200. Angled surfaces 214 and 224 located on the first and secondface 211 and 221, respectively, tend to move the belt away from therotational axis of the second pulley as the first sheave 210 and secondsheave 220 of the second pulley 200 move towards each other under thebias of spring 240. Thus, when tension decreases in the belt 300, thebias of the spring 240 moves the first and second sheaves 210 and 220together to decrease the width of groove 230. The belt 300 is thencaused to move further from the rotational axis of the second pulley,thus slowing the rotational speed of both the second pulley 200 and thedrive mechanism to which the second pulley 200 is connected. Bycontrast, when the belt 300 is tensioned (e.g., when the controlmechanism 500 is activated to cause the actuator 400 to move the firstpulley sheaves 110 and 120 towards each other to “clutch” the belt 300into motion/tension), the tension in the belt 300 overcomes the bias inthe spring 240 to separate the first and second sheaves 210 and 220 ofthe second pulley, thus widening the groove 230. As the groove 230widens, the belt 300 rides inward along the first and second face 211and 221 of the second pulley 200 towards the rotational axis of thesecond pulley. As the belt 300 approaches the rotational axis of thesecond pulley 200, the radius of rotation about the pulley decreases andthe speed of rotation is therefore increased accordingly. Thus, thedrive mechanism is driven at increasing speeds as the belt 300 istensioned by the control mechanism 500. Because the groove width of boththe first and second pulleys 100 and 200 changes in opposite directionsduring tensioning (or loosening), a two-fold increase (or decrease) inspeed can be achieved at the output shaft of the second pulley 200.

[0059] As shown in FIGS. 11 and 12, the first pulley 100 actuator 400can be configured to attach between a mower blade 700 and the lowerhousing 800 of a mower. The right half of the split view of FIGS. 11 and12 depicts an embodiment in which many of the pulley 100 and actuator400 components are molded components and the first pulley is in themaximum speed position (e.g., the actuator 400 is actuated and the firstsheave 110 and second sheave 120 of the first pulley 100 are at theirminimum separation distance and the belt 300 is furthest from therotational axis of the drive shaft 600). The left half of the split viewof FIG. 11 depicts an embodiment in which many components of the pulley100 and actuator 400 are plate components and the first pulley 100 andactuator 400 are in a neutral position. However, belt 300 is shown atboth a neutral and high speed position in this portion of the splitfigure.

[0060]FIGS. 13 and 14 show other embodiments of the present invention inwhich a “blade brake clutch” 900 is incorporated onto the same driveshaft 600 as are the first pulley 100 and actuator 400. In thisembodiment, many of the components are shown as being made from metalplate material. However, each of these parts could also be manufacturedas molded components. The right half of the split view of FIGS. 13 and14 depict the blade brake clutch mechanism in its actuated position inwhich a separate blade clutch disengages the drive shaft from an outputmember and a blade brake is applied to the disengaged output member tostop rotation of the output member and any equipment, such as mowerblades, attached to the output member. The left half of the split viewsin FIGS. 13 and 14 depict the blade brake clutch in a non-actuatedposition in which the drive shaft 600 is connected and rotates an outputmember.

[0061] When the belt 300 rides in the first pulley 100, a preferablerange for the outer diameter of the first pulley 100 as measured fromthe outside of the belt varies from 48.2 mm at low speed/neutral, to68.2 at mid speed, to 88.2 mm at maximum speed. Similarly, when the belt300 rides in the second pulley 200, a preferable range for the outerdiameter of the second pulley 200 as measured from the outside of thebelt varies from 103 mm at low speed/neutral, to 83.5 mm at mid-speed,to 64 mm at maximum speed. Of course, the specific value for thediameter of the first and second pulley can change depending on theparticular application or desired speed ratio. The horsepower requiredfor driving a mower engine at 3100 rpm which includes a first and secondpulley with the above noted diameter variances between neutral andmaximum speed is approximately 0.16 hp when cruising, and 0.47 hp atmaximum load. In addition, the ground speed can vary from 1.22 mph to3.61 mph in the preferred embodiment of the invention.

[0062] In the above embodiments of the invention, the force required toactuate the actuator 400 can be relatively low such that a low tensionforce is required in the cable 515. This low tension force provides goodoperating stability and durability for the variable speed transmissionand also permits easy operation by users of the device.

[0063] Although the invention has been described with respect topreferred embodiments of the invention, it should be understood thatmany variations of these embodiments fall within the scope and spirit ofthe claimed invention. For example, the specific speed, horsepower anddiameter values described above could be changed to meet a particularapplication or to fulfill different objectives. In addition, theinvention could include an embodiment in which the actuator and firstpulley are attached to a driven shaft, and the second pulley asdescribed above could be attached to the drive shaft or engine outputshaft. The invention could also be mounted in many different ways to thepower equipment, including under the housing, above the housing and evenon the side of a piece of power equipment.

[0064] The actuator is disclosed as including a ball/ramp device 243 forcausing separation of the actuator plates. However, other known actuatordevices could be incorporated in the present invention without departingfrom the spirit and scope of the invention. For example, a Blade BrakeClutch mechanism, as disclosed in applicant's co-pending U.S. patentapplication Ser. No. 09/628,447, which is hereby incorporated byreference, could be used in place of the actuator mechanism disclosedabove. The actuator could also be attached to the power equipment indifferent manners. For example, the second (or lower) actuator platecould be fixed to the power equipment, and the first (or top) actuatorplate could be connected to a control device and rotate with respect tothe power equipment and second actuator plate.

[0065] Although the second pulley is disclosed as having a first sheaveand second sheave that are rotationally locked with respect to eachother, it is within the scope of the present invention to include firstand second sheaves that can rotate with respect to each other in thesecond pulley. Such a configuration could provide a smoother transitionwhen engaging the drive mechanism and/or actuator mechanism during speedchange. The first sheave and second sheave of the first pulley aredisclosed as being separate from each other. However, it is contemplatedthat these structures could contact each other or be separated by abearing or the like. In addition, the extension portion (or hub portion)of the first sheave of the first pulley could conceivably bedisconnected from the first sheave and ride freely on the drive shaft.Furthermore, the extension portion of the first sheave could possibly beeliminated from the configuration depending on the type of belt used andthe friction parameters of all moving parts.

[0066] Additionally, it is contemplated that the first pulley could belocated at different positions relative to the actuator, including aboveor below the actuator on the drive shaft, without departing from thescope of the invention. The first sheave could also be driven with thedrive shaft (instead of the second sheave being driven as disclosedabove) and the second sheave could be actuated to move towards the firstsheave to narrow the groove of the first pulley and move the belt intocontact with the rotating first sheave. In addition, the actuator andfirst pulley as described above could be located on the driven shaft ofthe transmission drive train, and the belt could be driven by a drivepulley that is configured similar to the second pulley described in theembodiment above. The actuator could be activated to cause a first orsecond sheave of the driven pulley to engage with the moving belt at thedriven pulley side of the transmission. In this arrangement, the beltwould be moving and the driven pulley would “clutch” the moving belt toeffect the variable speed transmission.

[0067] The relative sizes of the first and second pulley and belt can bevaried in accordance with the desired speed ratios and in accordancewith the design parameters of specific power equipment. In this sameregard, the actuator size can be varied as well. The materials out ofwhich the system is manufactured also varies widely, and includes castmetals, metal plating, plastics, rubbers, ceramic, etc. The selection ofmaterials will effect the amount of friction necessary to engage orclutch the belt, and therefore could be a significant consideration indesigning the invention for a particular application.

[0068] The control device could also be configured differently andremain within the scope of the present invention. For example, thecontrol mechanism could be a magnetic, hydraulic, pneumatic, bellcrankor other type actuation device, and possibly could be a solenoid orother electronic actuator device.

[0069] It will be apparent to those skilled in the art that variousmodifications and variations can be made in the transmission of thepresent invention without departing from the spirit or scope of theinvention. Thus, it is intended that the present invention covers themodifications and variations of this invention provided they come withinthe scope of the appended claims and their equivalents.

What is claimed is:
 1. A variable speed transmission, comprising: afirst pulley having a rotational axis and including a first face and asecond face, the first face being movable with respect to the secondface; a belt located adjacent the first face and the second face of thefirst pulley; and an actuator located adjacent the first pulley andadapted to move the first face to move with respect to the second facebetween a neutral position, an intermediate position and a full speedposition, the neutral position defined by the first face being locatedat a first position with respect to the second face, and the first facebeing rotatable relative to the second face, the intermediate positiondefined by the first face being located at a second position that iscloser to the second face than when the first face is located at thefirst position, the belt being in frictional engagement with the firstface and second face such that motion of one of the first face, secondface and belt causes another one of the first face, second face and beltto move, and the full speed position defined by the first face beinglocated at a third position that is closer to the second face than whenthe first face is located at the second position, the belt being locatedin a position further from the rotational axis of the first pulley thanwhen the first face is located at the second position.
 2. The variablespeed transmission of claim 1, further comprising: a second pulleyhaving a second pulley rotational axis and including a primary face anda secondary face, wherein the belt is located adjacent the primary faceand the secondary face.
 3. The variable speed transmission of claim 2,wherein the second pulley includes a biasing mechanism located adjacentand biasing the primary face towards the secondary face of the secondpulley.
 4. The variable speed transmission of claim 3, wherein thebiasing mechanism is a spring.
 5. The variable speed transmission ofclaim 2, further comprising: a drive shaft located along the rotationalaxis of one of the first pulley and the second pulley, and a drivenshaft located along the rotational axis of the other of the first pulleyand the second pulley.
 6. The variable speed transmission of claim 5,wherein the drive shaft is connected to rotate with one of the secondface of the first pulley and the secondary face of the second pulley. 7.The variable speed transmission of claim 2, wherein the primary face andthe secondary face are movable with respect to each other.
 8. Thevariable speed transmission of claim 7, wherein the belt is located at aprimary position with respect to the second pulley rotational axis whenthe first face and second face of the first pulley are located in theneutral position, and the belt is located at a secondary position,closer to the second pulley rotational axis than when the belt islocated in the primary position, when the first face and second face ofthe first pulley are located in the full speed position.
 9. The variablespeed transmission of claim 7, wherein the primary face of the secondpulley is located closer to the secondary face of the second pulley whenthe first face and second face of the first pulley are located in theneutral position as compared to when the first face and second face ofthe first pulley are located in the full speed position.
 10. Thevariable speed transmission of claim 1, wherein the belt is spaced fromone of the first face and second face of the first pulley when the firstface and second face are located in the neutral position.
 11. Thevariable speed transmission of claim 1, wherein the actuator is aball/ramp type actuator.
 12. The variable speed transmission of claim 1,further comprising: a control mechanism connected to the actuator andconfigured to cause the actuator to move the first face of the firstpulley with respect to the second face.
 13. The variable speedtransmission of claim 12, wherein the control mechanism includes acontrol line connected to the actuator, and movement of the control linecauses the actuator to move the first face of the first pulley withrespect to the second face such that movement of the control linebetween three separate positions causes the first face and second faceof the first pulley to move between the neutral, intermediate and fullspeed positions, respectively.
 14. The variable speed transmission ofclaim 1, further comprising: means for causing the actuator to move thefirst face of the first pulley with respect to the second face.
 15. Thevariable speed transmission of claim 1, wherein the first face of thefirst pulley includes a first portion extending along the rotationalaxis of the first pulley, and the belt is connected to the first portionof the first face when the first face is in the neutral position. 16.The variable speed transmission of claim 1, wherein the first face andsecond face of the first pulley angle towards each other as theyapproach the rotational axis of the first pulley, such that when thefirst face and second face move towards each other, the belt is forcedby the first and second face away from the rotational axis of the firstpulley.
 17. A variable speed transmission for continuously varying theoutput speed of a drive wheel from zero to an upper speed limit,comprising: a single control mechanism capable of controlling the speedof the drive wheel from zero to the upper speed limit; an actuatorconnected to the control mechanism; and a drive train operationallyconnected between the control mechanism and the drive wheel, wherein thedrive train includes a first and second pulley and no more than onebelt.
 18. A variable speed transmission for continuously varying theoutput speed of a drive wheel from zero to an upper speed limit,comprising: a single control mechanism capable of controlling the speedof the drive wheel from the upper speed limit to zero; an actuatorconnected to the control mechanism; and a drive train operationallyconnected between the control mechanism and the drive wheel, wherein thedrive train includes a first and second pulley connected by a belt, thefirst pulley having a rotational axis, a first face and a second face,the first face being movable with respect to the second face; whereinthe actuator is located adjacent the first pulley and capable of causingthe first face to move with respect to the second face between a neutralposition, an intermediate position and a full speed position, theneutral position defined by the first face being located at a firstposition with respect to the second face, and rotatable with respect tothe first face, the intermediate position defined by the first facebeing located at a second position that is closer to the second facethan when the first face is located at the first position, the beltbeing in frictional engagement with the first face and second face suchthat motion of one of the first face, second face and belt causesanother one of the first face, second face and belt to move, and thefull speed position defined by the first face being located at a thirdposition that is closer to the second face than when the first face islocated at the second position, the belt being located in a positionfurther from the rotational axis of the first pulley than when the firstface and second face are in the intermediate position.
 19. A variablespeed transmission, comprising: a first pulley having a rotational axisand including a first face and a second face, the first face beingmovable with respect to the second face;. a second pulley having asecond pulley rotational axis and including a primary face and asecondary face; a belt located on the first pulley and second pulley;and an actuator located adjacent the first pulley and adapted to movethe first face with respect to the second face between a neutralposition and a drive position, the neutral position is defined by thefirst face being located at a first position with respect to the secondface, and the first face being rotatable with respect to the secondface, the drive position is defined by the first face and second facebeing frictionally engaged with the belt such that the first face,second face and belt rotate together.
 20. A variable speed transmission,comprising: a first pulley having a rotational axis and including afirst face and a second face, the first face being movable with respectto the second face; a second pulley having a second pulley rotationalaxis and including a primary face and a secondary face, the primary facebeing movable with respect to the secondary face along the second pulleyrotational axis; a biasing mechanism located adjacent one of the primaryface and secondary face of the second pulley and adapted to bias theprimary face towards the secondary face; a belt located on the firstpulley and second pulley; and an actuator located adjacent the firstpulley and adapted to move the first face with respect to the secondface between a neutral position and a drive position, the neutralposition is defined by the first face being located at a first positionwith respect to the second face, and the first face being rotatable withrespect to the second face, the drive position is defined by the firstface and second face being frictionally engaged with the belt such thatthe first face, second face and belt rotate together.
 21. The variablespeed transmission of claim 20, wherein the biasing mechanism is aspring.
 22. The variable speed transmission of claim 20, wherein theprimary face of the second pulley includes an opening, and the secondaryface includes a hub that can be inserted into the opening in the primaryface.
 23. The variable speed transmission of claim 22, wherein thesecond pulley includes an attachment plate connected to the hub of thesecondary face such that movement of the primary face with respect tothe secondary face is limited by the attachment plate, and the biasingmechanism is located between the primary face and the attachment platesuch that the primary face is biased away from the attachment plate andtowards the secondary face.
 24. The variable speed transmission of claim20, wherein the actuator is adapted to move the first face with respectto the second face between the neutral position, the drive position anda full speed position, the full speed position is defined by the firstface being located at a position that is closer to the second face thanwhen the first face is located at the second position, the belt beinglocated in a position further from the rotational axis of the firstpulley than when the first face and second face are in the driveposition.
 25. A method for using a variable speed transmission thatincludes a first pulley having a rotational axis, a first face and asecond face, the first face being movable along the rotational axis withrespect to the second face, a belt located adjacent the first face andthe second face of the first pulley, comprising: driving one of thefirst face, the second face and the belt about the rotational axis ofthe first pulley; moving the first face along the rotational axis andrelative to the second face such that a portion of each of the firstface and the second face frictionally engages the belt to cause one ofthe first face, the second face and the belt to begin movement about therotational axis of the first pulley; and moving the belt away from therotational axis of the first pulley to cause the belt to move fasterabout the rotational axis of the first pulley.
 26. The method for usinga variable speed transmission of claim 25, wherein moving the belt awayfrom the rotational axis of the first pulley includes continuing movingthe first face along the rotational axis towards the second face suchthat the belt is forced away from the rotational axis by the first andsecond face of the first pulley.
 27. The method for using a variablespeed transmission of claim 25, wherein moving the first face along therotational axis of the first pulley towards the second face includesactivating an actuator located adjacent the first pulley.
 28. The methodfor using a variable speed transmission of claim 25, wherein theactuator is a ball/ramp type actuator.
 29. The method for using avariable speed transmission of claim 25, wherein activating the actuatorincludes moving a control line between a neutral position and a secondposition.
 30. The method for using a variable speed transmission ofclaim 29, further comprising: providing a driven wheel, wherein movingthe control line causes the driven wheel to; be substantially motionlesswhen the control line is located at the neutral position, begin rotationwhen the control line is moved from the neutral position to anintermediate position, and increase in rotational speed as the controlline is moved from the intermediate position to the second position. 31.The method for using a variable speed transmission of claim 25, furthercomprising: providing a second pulley having a rotational axis, a driveshaft located along the rotational axis of one of the first pulley andthe second pulley, and a driven shaft located along the rotational axisof the other of the first pulley and the second pulley.
 32. The methodfor using a variable speed transmission of claim 31, wherein the secondpulley includes a primary face and a secondary face, the method furthercomprising: moving the primary face of the second pulley away from thesecondary face as the first face of the first pulley moves towards thesecond face.
 33. The method for using a variable speed transmission ofclaim 25, wherein the first face of the first pulley includes anextension portion extending along the rotational axis of the firstpulley, the method further comprising: supporting the belt on theextension portion of the first face prior to the step of moving thefirst face along the rotational axis towards the second face of thefirst pulley.
 34. The method for using a variable speed transmission ofclaim 25, wherein the first face and second face of the first pulleyangle towards each other as they approach the rotational axis of thefirst pulley, such that when the first face is moved towards the secondface, the belt is forced by the first and second face away from therotational axis of the first pulley.
 35. The method for using a variablespeed transmission of claim 25, further comprising: providing a secondpulley that has a second pulley rotational axis and includes a primaryface and secondary face, the second pulley being connected to the belt;biasing the primary face towards the secondary face; rotating the beltabout the second pulley rotation axis; moving the belt in one of a firstand second direction, the first direction being towards the secondpulley rotational axis and causing the second pulley to rotate faster,and the second direction being away from the second pulley rotationalaxis and causing the second pulley to rotate slower.
 36. The method forusing a variable speed transmission of claim 35, wherein moving the beltaway from the rotational axis of the first pulley includes causing thebelt to move towards the second pulley rotational axis to cause thesecond pulley to rotate faster.
 37. A method for using a variable speedtransmission that includes a first pulley having a rotational axis, afirst face and a second face, the first face being movable along therotational axis with respect to the second face, a second pulley havinga second pulley rotational axis, a primary face and a secondary face,the primary face being movable with respect to the secondary face alongthe second pulley rotational axis, a belt connected between the firstpulley and the second pulley, comprising: driving one of the first face,the second face and the belt about the rotational axis of the firstpulley; moving the first face along the rotational axis and relative tothe second face such that a portion of each of the first face and thesecond face frictionally releases from the belt to cause one of thefirst face, the second face and the belt to begin movement relative toanother one of the first face, the second face and the belt.
 38. Themethod for using a variable speed transmission of claim 37, whereinmoving the first face along the rotational axis and relative to thesecond face such that a portion of each of the first face and the secondface frictionally releases from the belt includes slowing one of thefirst face, second face and belt to substantially zero speed relative tothe other of the first face, second face and belt.
 39. The method forusing a variable speed transmission of claim 37, wherein prior to movingthe first face along the rotational axis and relative to the second facesuch that a portion of each of the first face and the second facefrictionally releases from the belt, the method includes: moving thebelt in one of a first and second direction, the first direction beingtowards the first pulley rotational axis and away from the second pulleyrotational axis, causing the belt to move slower about the first pulleyrotational axis and causing the second pulley to rotate slower about thesecond pulley rotational axis, and the second direction being away fromthe first pulley rotational axis and towards the second pulleyrotational axis, causing the belt to move faster about the first pulleyrotational axis and causing the second pulley to rotate faster about thesecond pulley rotational axis.
 40. The method for using a variable speedtransmission of claim 39, wherein moving the belt in the seconddirection includes providing a biasing mechanism on the second pulleyand biasing the primary face and secondary face towards each other tomove the belt away from the second pulley rotational axis.
 41. Themethod for using a variable speed transmission of claim 39, whereinmoving the belt in one of a first and second direction includesproviding an actuator that can be moved between a neutral position and adrive position to move the first face and second face towards and awayfrom each other causing the belt to move away from and towards therotational axis of the first pulley, respectively.
 42. The method forusing a variable speed transmission of claim 41, further comprising:providing a driven wheel, wherein moving the actuator between theneutral position and the drive position includes causing the drivenwheel to; be substantially motionless when the actuator is located atthe neutral position, begin rotation when the actuator is moved from theneutral position towards the drive position, increase in rotationalspeed when the actuator continues movement from the neutral positiontowards the drive position, and decrease in rotational speed when theactuator is moved towards the neutral position.
 43. A method for using avariable speed transmission to drive a propulsion mechanism on a pieceof power equipment, comprising: providing a control mechanism that isconnected to a drive train which drives the propulsion mechanism, thedrive train including a first pulley having a rotational axis, a firstsheave and a second sheave, and a belt having an inner surface locatedaround the first pulley; permitting the first sheave to remainsubstantially stationary relative to the second sheave; rotating thefirst sheave of the first pulley with respect to the belt; and engagingthe belt with the first sheave of the first pulley with enough force tobegin movement of the belt about the first pulley.
 44. The method ofclaim 43, wherein the first sheave of the first pulley includes a firstface and the second sheave of the first pulley includes a second face,and the first face and second face form a groove and face each other,and wherein the engaging of the belt includes contacting the belt withthe first face of the first sheave of the pulley to begin movement ofthe belt about the first pulley.
 45. The method of claim 44, wherein theengaging of the belt includes moving the first face along the rotationalaxis towards the second face such that a portion of each of the firstface and the second face frictionally engages the belt with enough forceto cause the belt to begin movement about the rotational axis of thefirst pulley.
 46. The method of claim 45, further comprising: moving thebelt away from the rotational axis of the first pulley to cause the beltto move faster about the rotational axis of the first pulley.